Lumphini Park is the city's lung, and it is at its best between six and nine. Get there early.
Enter at the north gate by 07:00. The lake loop is 2.5 km, flat, and at this hour shared with tai chi groups, runners, and the occasional monitor lizard. One slow circuit is forty minutes; you'll have done more for your jet lag than any nap.
Walk south across Wireless Road into One Bangkok — the new district that opened last year, all glass towers and ground-floor coffee. Arabica's Kyoto-style counter and a-keen-house's breakfast set are both within a hundred metres of each other; pick one for coffee and the other for food. Sit outside if the rain holds.
From One Bangkok, the new sky bridge runs east directly into Benjakitti Forest Park — Bangkok's newest park, an elevated boardwalk through wetlands that feels nothing like a city. The walk is fifteen minutes, all in shade.
Close at Kamthieng House, a 19th-century Lanna teakwood home reassembled in the middle of Sukhumvit. It's a five-minute walk from the park's east exit and it stays cool inside. By the time you're done it's noon and the day is still ahead of you.
