Tens of thousands get sneak peek of Japan Imperial Palace

 Tens of thousands of people were offered a rare -- but congested -- glimpse of Japan's exclusive Imperial Palace grounds in Tokyo Wednesday, in a fleeting open garden event, AFP reports.

By early afternoon, more than 50,000 visitors had turned out to enjoy a stroll along a 750-metre (820-yard), tree-lined road that is usually off-limits to the hoi polloi.

Television footage, including from helicopters, showed ranks of mostly elderly people shuffling through the dramatic autumn foliage of crimson maple trees.

The Imperial Household Agency, the government department responsible for every aspect of the royal family's affairs, decided to open a small section of the grounds for five days as part of celebrations marking Emperor Akihito's 80th year.

The Imperial Palace is a vast patch of greenery in grey, crowded Tokyo, one of the biggest cities on earth, where millions of people live in cramped apartments.

Surrounded by a moat, the grounds were the site of a magnificent castle for the storied shogun warlords of yesteryear, but became the main residence for the royal family after the so-called "Meiji Restoration" of 1868 brought the emperor back to pre-eminence.

During Japan's property bubble of the 1980s, it was said that the palace grounds were worth more as a piece of real estate than the entire state of California.

Although Akihito's father was forced to renounce his divinity as part of Japan's surrender in World War II, the imperial family remains highly revered by most Japanese.

The arcane traditions that surround every aspect of their lives are a mystery to the public, which eagerly leaps on any chance to peer behind the curtain, however briefly.