Police arrested at least 26 young activists for causing "public nuisance" at a protest ahead of Chinese President Xi Jinping's arrival in Hong Kong. Animosity towards Beijing has grown among young people in Hong Kong in recent years, with some demanding a full split from the mainland. A protest on July 1, the day of the anniversary, could draw up to 100,000 people.

Protesters previously draped a black sheet over the "Forver Blooming Gold Bauhinia" sculpture. The statue, which depicts Hong Kong's sweet-smelling official emblem, was given to the city by China to mark the 1997 handover. It is located outside a convention center that will host some of the anniversary events and is close to where Chinese President Xi Jinping will be staying.

Around 30 protesters gathered at the "Golden Bauhinia" statue on Wednesday, climbing on its petals and forming chain around its base. The demonstrators inside the flower were the last to be removed and were helped down by firefighters.

The activists held a three-hour sit-in around the sculpture before police began leading them away one-by-one. Prior to the arrests, the demonstrators shouted: "Civil disobedience, no fear!" and "Xi Jinping, can you hear us?"

Student protest leader Joshua Wong (center) was among those arrested on Wednesday evening. Although other protesters were led from the scene, Wong lay down on the ground and was carried from the scene into a police van. He was one of the leaders of the Umbrella Movement in 2014 which saw mass rallies in Hong Kong. Their calls for democratic reforms ultimately failed to win concessions.

Hong Kong's youngest lawmaker and former Umbrella Movement leader Nathan Law (center) was also carried away by police and remained in custody. The 23-year-old was elected to the legislature last year.

President Xi is visiting Hong Kong for celebrations to mark the 20th anniversary of Britain's handover of the territory to China on July 1. But there are concerns that Beijing has been violating the "one country, two systems" deal by interfering in politics, education and media.

To access the premises of an abandoned British army barracks, these self-proclaimed "big city explorers" must wiggle through a hole in a wire mesh fence. It is the beginning of a trip through Hong Kong's past.

The dilapidated remains of buildings emerge behind the fence - where British soldiers once were housed, there is silence, empty rooms and smashed windows. The urban explorers want to make sure these scenes and the history that shaped them aren't forgotten.

The explorers delve into the barracks' farthest, darkest corners, always on the lookout for so-called "lost places" they can photograph or film for posterity. They are hot on the heels of the global "urban exploration" trend.

The exploratory tours through colonial-era homes, military properties and public buildings are for the most part clandestine, and not authorized. To avoid hassles from Hong Kong authorities, the young artists keep their identities secret and hide their faces behind masks.

St. John's Cathedral is one of more than 1,000 historic buildings languishing in the shadows of the towering Hong Kong skyline. Only 114 buildings are listed as protected, and even fewer are actually being restored. The urban explorers urge more commitment, appealing to the authorities to actively restore structures that are part of the city's identity.

Why document the state of Hong Kong's colonial-era buildings? Wedged between looming skyscrapers and bustling vegetable stalls, many are slowly decaying. In 20 years, not much will be left of Hong Kong's unique legacy and its architecture, one of the urban explorer group's co-founders fears.

Sometimes, the exploring artists find unique colonial-era documents, like this 1982 newspaper, which shines a light on the history of a British crown colony that had difficult relations with communist China and ambivalent feelings toward London.

The Hong Kong urban explorers have visited and documented more than 50 colonial-era sites, including this almost 100-year-old mansion. The photographs and videos are posted on the Internet. They may not all recall Hong Kong's complicated political and military history, but they bear silent witness to a bygone era.