Standing on the grounds of the State Guesthouse, Akasaka Palace on a crisp autumn day in November, it's hard to believe you're in central Tokyo, just a few minutes' walk from bustling Yotsuya Station. Birds can be heard chirping in the nearby garden and, aside from catching the occasional word or two from other visitors engaged in conversation in the distance, the overall atmosphere is tranquil.

It's just the ambience you might hope to find at a guesthouse, let alone a residency that used to belong to the imperial family and the added bonus of historical significance. The guesthouse has come a long way, however. Its role in society has changed over time. It has hosted a number of prominent global figures, including Britain's Queen Elizabeth II, and continues to help anchor Japan's diplomatic efforts at home. Ten years ago — on Dec. 8, 2009 — the palace was designated a National Treasure, virtually cementing its standing as an asset for future generations.

Most recently, the palace has served as the venue for dozens of meetings between Prime Minister Shinzo Abe and foreign dignitaries that included South Korean Prime Minister Lee Nak-yon, Chinese Vice President Wang Qishan and Myanmar leader Aung San Suu Kyi. Abe met with dignitaries from about 50 countries in the space of just five days.