盛开的白延龄草，安大略省，加拿大 White trillium blooming in Ontario, Canada (© Jun Zhang/Getty Images)

嘿，今天长势如何？ Hey, how's it growing today?

安大略省的白延龄草，加拿大

三片花瓣、三片叶子和三个柱头——这就是白延龄草，它的名字源自拉丁语中的“三”，原产于北美东部，是春季最常见的林地野花之一。与一些稍有暖意就绽放色彩的“冲动型”花朵不同，这种植物开花缓慢。从美国邮票上的图案到俄亥俄州的州花，再到加拿大安大略省的官方象征，白延龄草扎根于各国文化。除了美观之外，白延龄草在草药界也有一席之地。所以，你在林间漫步时，请留意这种花卉珍品！

White trilliums blooming in Ontario, Canada

Three petals, three leaves, and three stigmas—that's the white trillium for you, whose name derived from the Latin word for 'three.' Native to eastern North America, the spring-blooming species is one of the most common woodland wildflowers. Unlike some impulsive blossoms that burst into color at the slightest hint of warmth, this plant is a slow bloomer. From gracing US postage stamps to being the state wildflower of Ohio and an official symbol of Canada's Ontario, the white trillium is ingrained in our culture. Beyond its aesthetic appeal, the plant has earned its stripes in the world of herbal medicine. So, next time you find yourself wandering through the woodland realm, keep an eye out for this floral gem!

三一学院图书馆，都柏林，爱尔兰 Library of Trinity College Dublin, Ireland (© Lukas Bischoff/Getty Images)

预订已满！ Fully booked!

世界读书日

在爱尔兰中心，在都柏林三一学院图书馆历史悠久的大厅里，卷轴和古籍低声诉说着久远的故事。今天，这些沉默的故事讲述者将大放异彩。世界图书日由联合国教科文组织于1995年设立，旨在提醒人们阅读、出版和版权的重要性。但为什么是4月23日呢？因为这一天是威廉·莎士比亚、米格尔·德·塞万提斯和其他几位文学巨匠共同的忌日！从每年在马里兰州肯辛顿举办的汇集众多作家、诗人和文学组织的街头庆祝活动，到世界各地许多国家向孩子们分发图书券，这一天在书页翻动的沙沙声中变得生机勃勃。有趣的是，联合国教科文组织每年都会推选一个城市为“世界图书之都”，被选中的城市将在被授予的一年中开展促进阅读的活动，今年当选是法国斯特拉斯堡。那么，你选好要读的书了吗？

World Book Day

In the heart of Ireland, amidst the storied halls of the Library of Trinity College Dublin, scrolls and tomes whisper tales of long-gone eras. Today, these silent storytellers shine for World Book Day. Established by UNESCO in 1995, the day serves as a reminder of the importance of reading, publishing, and copyright. But why April 23? It marks the shared death anniversary of William Shakespeare, Miguel de Cervantes, and several other literary greats. From the annual street festival exhibiting authors, poets, and literary organizations in Kensington, Maryland, to the distribution of book vouchers to kids in many countries around the world, this day comes alive with the rustle of turning pages. Interestingly, each year, UNESCO crowns one city as the 'World Book Capital.' The chosen city then carries out activities aimed at promoting reading for the awarded year; this year it is Strasbourg, France. So, have you picked out a book to read yet?

Cades Cove ，大雾山国家公园，田纳西州，美国 Sparks Lane in Cades Cove, Great Smoky Mountains National Park, Tennessee (© Richard Bernabe/Shutterstock)

未选择的路 The road not taken

国家公园周活动继续开展

随着美国国家公园周活动的开展，让我们一起去田纳西州的大雾山国家公园走走吧！该公园成立于1934年，占地面积超过522,419英亩。这座公园的大部分地区都被森林覆盖着，是1500种开花植物、952种藻类、65种哺乳动物和240多种鸟类的家园，大雾山国家公也因此成为了国际生物圈保护区。

在今天的照片中看到的开字山凹是大雾山国家公园内的一个山谷，以其迷人的风景和历史建筑（包括小木屋、谷仓和教堂）而闻名。在探索公园的同时，你还可以参观咆哮叉机动车自然小径、卡特罗基山和埃尔克蒙特等历史名胜。如果你想看萤火虫，埃尔克蒙特就是你的不二之选。如果你是一名地质学家，这里也有适合你的东西：这个公园是前寒武纪晚期岩石的家园。所以，释放你的冒险精神，与其他人一起去探索国家公园吧！

National Park Week continues

As National Park Week unfurls its green banners, let's take a stroll down Sparks Lane, in Great Smoky Mountains National Park, Tennessee. Established in 1934, the park encompasses over 522,419 acres of wilderness, mostly covered with forests. It is home to 1,500 species of flowering plants, 952 algae, 65 species of mammals, and over 240 species of birds, making it an International Biosphere Reserve.

Cades Cove—seen in today's photo—is a valley renowned for its scenery and historic structures, including log cabins, barns, and churches. While exploring the park, you can also visit historical areas like Roaring Fork, Cataloochee, and Elkmont. If you wish to watch fireflies, then Elkmont is the place for you, and if you are a geologist, there's something for you too: This park is home to late Precambrian rocks. So, set your spirit of adventure free and join others to celebrate the timeless American treasure: national parks!

日出时分的大棱镜泉，美国怀俄明州黄石国家公园 Grand Prismatic Spring at sunrise, Yellowstone National Park, Wyoming (© XIN WANG/Getty Images)

保存，保护，享受！ Preserve, protect, enjoy!

国家公园周开幕

准备好你的登山靴吧，因为美国国家公园周到了！美国各地最迷人的风景区已敞开大门，邀请大家免费拥抱大自然。在整个庆祝活动期间，美国国家公园管理局将组织各种活动，包括由护林员带领的参观活动、志愿者活动和教育研讨会。

如果你在怀俄明州，您可能想去黄石国家公园看看。作为世界上第一个国家公园，该公园以其植物群、动物群（包括落基山狼、灰熊和黑熊）、超级火山和许多地热景观而闻名，而今天的图片上的大棱镜泉正是其中之一。位于中间歇泉盆地的大棱镜泉从里向外呈现出蓝、绿、黄、橙、红等不同颜色，这种现象是由水体中生活的藻类和含色素的细菌等微生物造成的。外面有太多的东西等着你去探索，所以快召集你的朋友，到野外去吧。

National Park Week begins

Get ready to lace up your hiking boots, because National Park Week is upon us! Across the country, America's most stunning landscapes throw their gates wide open, inviting everyone to embrace the great outdoors for free. Throughout the celebration, various programs will be organized by the National Park Service, including ranger-led tours, volunteer opportunities, and educational workshops.

If you are in Wyoming, you might want to visit Yellowstone, the world's first national park. Established in 1872 by President Ulysses S. Grant, the park is known for its flora, fauna—including Rocky Mountain wolves, and grizzly and black bears—supervolcano, and many geothermal features, including the one we see in today's image. The Grand Prismatic Spring is in the Midway Geyser Basin. Its display of colors is caused by multi-layered sheets of microorganisms, ranging from deep blues and greens to fiery oranges and reds. There is so much waiting to be explored out there, so gather your friends and get out into the wild.

布罗德加环，奥克尼岛，苏格兰 The Ring of Brodgar, Orkney, Scotland (© Paul Williams - FunkyStock/Getty Images)

历史的轮回 History has come full circle

布罗德加环，奥克尼岛，苏格兰

在苏格兰北部的奥克尼群岛的中心地带，有一个古老的谜团：布罗德加环。这个新石器时代的石圈是一种古老的圆形土方工程，可以追溯到公元前2500年到2000年之间，石圈的直径约为340英尺。该遗址位于两个湖泊之间的狭长地带，最初由60块石头组成，如今只剩下36块。该石圈的确切用途至今仍不得而知。为了进一步了解该遗址，一项名为“挖掘布罗德加环”的发掘项目于2008年启动，但该项目尚未取得任何结论性成果。1999年，包括布罗德加环在内的新石器时代的奥克尼中心地带被联合国教科文组织列为世界遗产。如果你计划去苏格兰旅行，不妨去布罗德加环逛逛。在这里，你不仅可以呼吸到清新的空气，还可以感受石圈的悠久历史。

Ring of Brodgar, Orkney, Scotland

At the heart of the Orkney Islands, an archipelago in northern Scotland, lies an ancient riddle: the Ring of Brodgar. Dating back to sometime between 2500 and 2000 BCE, this Neolithic henge—a type of ancient circular earthwork—and stone circle measure about 340 feet across. Lying on a narrow strip of land between two lochs, the site initially comprised 60 stones, although today only 36 remain. The exact purpose of the structure is still unknown, despite an excavation project at the site in 2008. In 1999, the Heart of Neolithic Orkney group of monuments, which includes the Ring of Brodgar, was recognized as a UNESCO World Heritage Site. If you are planning a trip to Scotland, consider walking amid the echoes of history at the Ring of Brodgar while the crisp Scottish air embraces you.

中世纪城墙，阿维拉，西班牙 Medieval city walls, Ávila, Spain (© Scott Suriano/Getty Images)

名誉之墙 Wall of fame

国际古迹遗址日

今天是一个具有纪念意义的日子：国际古迹遗址日。这一天也被称为“世界遗产日”，旨在强调保护文化遗产的重要性。从建筑物到雕塑，古迹可以是任何一样东西，只要它在历史、艺术或科学层面具有突出的价值。世界上有许多令人惊讶的古迹，例如秘鲁的马丘比丘和埃及的吉萨金字塔等，而今天的图片展示的是一个石头建筑，它是西班牙阿维拉中世纪城墙的其中一部分。这些碉堡修建于11世纪至14世纪，周长超8000英尺，最初的修建目的是保护城市，抵御外来者的进攻，如今这里成为了旅游圣地，游客们可以沿着城墙漫步，欣赏城市和周围乡村的美景。

International Day for Monuments and Sites

Happy International Day for Monuments and Sites! Also called World Heritage Day, the event highlights efforts to conserve our cultural heritage. Some of the amazing heritage sites around the world include Machu Picchu in Peru and the Pyramids of Giza in Egypt. The stone structure in today's image is part of the medieval city walls of Ávila in Spain. Built between the 11th and 14th centuries to defend the city against attack, these fortifications stretch for 1.5 miles around Ávila. Nowadays, visitors can walk around sections of the walls, enjoying views of the city and the surrounding countryside.

暮色中的曼哈顿下城联合广场，纽约，美国 Union Square in lower Manhattan at twilight, New York (© Sean Pavone/Getty Images)

灯光，相机，纽约！ Lights, camera, New York!

联合广场，曼哈顿，纽约

“纵横交错的街道令人焕然一新，璀璨的霓虹灯让人热血沸腾。” 流行歌手艾丽西亚·凯斯在歌曲《帝国之心》中这样描述大苹果市（纽约的别称）的繁华与活力。今天，主页的图片将我们带到 “不夜城 ”的其中一个景点：曼哈顿下城的联合广场。在这个历史悠久的十字路口，您可以看到乔治·华盛顿的雕像，它是纽约市所有公园中最古老的雕像，以及雕塑家亨利·柯克·布朗创作的亚伯拉罕·林肯的雕像。1882年，工人们行使他们言论自由和集会自由的权利，在联合广场组织了第一次劳动节游行。正因如此，联合广场在美国劳工史上具有特殊的意义，1997年美国内政部将其认定为国家历史地标。时光飞逝，如今的曼哈顿更加繁华，当你漫步在街头，或许会在广场上看到街头棋手、音乐家、滑板爱好者、舞蹈团体和各类小贩。

Union Square, Manhattan

'These streets will make you feel brand new, big lights will inspire you.' Alicia Keys sure knows how to serenade the vibrant, bustling life of the Big Apple. Today's homepage image takes us to Union Square in lower Manhattan. At this historic intersection, you can find statues of George Washington—the oldest statue in any park in NYC—and Abraham Lincoln, crafted by the sculptor Henry Kirke Brown. In 1882, workers exercised their rights to free speech and assembly, organizing the first Labor Day parade here. In 1997, Union Square was recognized as a National Historic Landmark due to its importance in US labor history. These days, you're more likely to see street chess players, musicians, skateboarders, dance crews, and vendors of all types in the square.

红球项目艺术装置，安特卫普中央车站, 比利时 The RedBall Project art installation, Centraal Station, Antwerp, Belgium (© Brit Worgan/Getty Images)

激发创造力 Bouncing into creativity

世界艺术日

“艺术是所有科学的女王，将知识传达给世界上的每一代人。”让我们在4月15日世界艺术日，也就是这位文艺复兴时期著名艺术家的生日，思考一下达的这些鼓舞人心的话。从他标志性的蒙娜丽莎画作到他详细的飞行机器草图，莱昂纳多在广泛的领域突破了知识和才华的界限。今天的主页展示了比利时安特卫普中央车站的红球项目。这个巡回公共艺术装置由美国艺术家Kurt Perschke创作，被认为是世界上运行时间最长的街头艺术作品。自2001年以来，这个15英尺高的充气红球已经被楔入从澳大利亚到英国的数十个国家的地标。

World Art Day

'Art is the queen of all sciences communicating knowledge to all the generations of the world.' Let’s ponder these inspirational words by Leonardo da Vinci on World Art Day, April 15, which was also the birthday of the renowned Renaissance artist. From his iconic painting of the Mona Lisa to his detailed sketches of flying machines, Leonardo pushed the boundaries of knowledge and talent in a wide range of fields. Today's homepage shows the RedBall Project at Centraal Station in Antwerp, Belgium. Created by the American artist Kurt Perschke, this traveling public art installation is considered to be the world's longest-running street artwork. Since 2001, the 15-foot inflated red ball has been wedged into dozens of landmarks in countries from Australia to England.

香波城堡，中央-卢瓦尔河谷大区，法国 (© Susanne Kremer/eStock Photo)

介于文艺复兴与独创性之间

香波城堡，法国

你知道香波城堡吗？这个古建筑是法国文艺复兴时期的一颗“明珠”，其建筑灵感来源于法国国王弗朗西斯一世和著名画家达·芬奇。香波城堡的设计者是谁一直存在争议，至今没有定论，但可以确定的是，它的建筑特色受到了达·芬奇的影响。1515年马里尼亚诺战役后，弗朗西斯一世被意大利壮丽的建筑吸引，倾慕于达·芬奇的才华，他邀请达·芬奇来到法国宫廷担任艺术家和总工程师。香波城堡的中心平面设计和双螺旋楼梯见证了这一非凡的合作。主楼是这座建筑的真正核心，它融合了中世纪的宏伟与文艺复兴时期的创新，展示出了一种独特的引人注目的建筑风格。时光流转，这座古老的建筑见证着荣耀与兴衰，艺术、历史和技术在这里相遇，为游客们创造出一种难忘的体验。

保龄球海滩的日落，门多西诺县，加利福尼亚，美国 Sunset on Bowling Ball Beach, Mendocino County, California (© Melo Qiao/Getty Images)

岩石保龄球 Rock 'n' bowl

保龄球海滩，加利福尼亚州

欢迎来到大自然的保龄球馆！位于加州门多西诺海岸的保龄球海滩以散布在海岸上的那些引人注目的岩石而命名。这些砂岩球（一种被称为结核的现象）是在数百万年的沉积过程中形成的，沉积层围绕着由矿物胶结物固定在一起的砂石核心堆积而成。侵蚀作用逐渐磨损了外层，露出我们今天看到的球形。这创造了一个只有在退潮时才会出现的迷人景象。这种砂岩球很罕见，人们对它们的来源有很多疯狂的猜测，有人认为它们是外星碎片，也有人怀疑它们是恐龙化石。然而，答案非常简单：这是大自然的力量在起作用。

Bowling Ball Beach in Mendocino County, California

Welcome to nature's bowling alley. Bowling Ball Beach on the Mendocino Coast in California is named after the striking rock formations strewn across the shore. These sandstone balls—a phenomenon known as concretions—formed over millions of years as sedimentary layers built up around a central core of sand and stone held together by mineral cements. Erosion gradually wore away the outer layers to expose the spherical shapes we see today. This created a fascinating spectacle that only appears at low tide. Concretions are rare, and there has been plenty of wild speculation about where they come from, with some believing them to be extraterrestrial debris while others wonder if they are dinosaur fossils. The answer, however, is quite simple: It is the forces of nature at play.