Every guidebook mentions Lumpini Park but it's honestly nothing special during busy periods. Gets crowded by mid-morning, smells like pond water, and full of aggressive monitor lizards

Benjakitti Park (in Klong Toey district, accessible via BTS and short taxi/walk) is much nicer — Clean lake, better walking paths, modern facilities, and way fewer tourists trying to feed dangerous wildlife. Open 5 AM-9 PM, free entry, and you can actually relax there without dodging tour groups