Asia's megacities have a reputation for being impossible to walk. That is half-true. The highways and the scale are often intimidating, but almost every major Asian city has pockets — sometimes small, sometimes enormous — that are as walkable as anywhere in Europe.
Tokyo is the hidden champion. The density of small streets and shop-lined alleyways makes most of central Tokyo extraordinarily walkable. Shimokitazawa, Yanaka, Shibuya, Daikanyama, the alleys of Shinjuku — every one a walking city unto itself.
Seoul has been a revelation of the last decade. Seongsu-dong, Ikseon-dong's hanok alleys, Yeonnam-dong along the Gyeongui Line Forest — Seoul is now one of the best walking cities in Asia.
Singapore is Asia's most planned walkable city. Tiong Bahru, Kampong Glam, Katong and Chinatown are all proper walking neighborhoods, well-shaded, well-signposted.
Bangkok surprises people. The sois off Sukhumvit — Ari, Thonglor, Ekkamai — are deeply walkable once you are inside them. The challenge is crossing main roads.
Chiang Mai is all walkable. The Old City within the moat is a proper walking town.
Hanoi's Old Quarter is one of the best walking districts in Asia, chaos and all.
What these neighborhoods share: human-scaled blocks, street food, narrow lanes, and a density of interesting things per meter walked. In that respect, Asia's best neighborhoods are not so different from Europe's.