Bangkok's science and natural history institutions — underrated and genuinely worthwhile.
Located in Pathum Thani (north of Bangkok) — a large campus with Natural History, Science, and IT museums; excellent for families; 200 THB entry.
Bangkok's public planetarium near Siam — dome shows on astronomy; entry under 100 THB; smaller but atmospheric.
The Snake Farm, Museum Siam, and National Museum all have genuine educational value — Bangkok's institutions are underrated by most visitors.
MRT to end of line then taxi; about 40 minutes from central Bangkok — worth it as a half-day family trip.
Planetarium shows run on a fixed schedule with limited seating — check show times online and arrive 15–20 minutes early, since popular slots do sell out on weekends.
The Science Museum works well for a wide age range with hands-on exhibits for younger kids and deeper technical content for teens; the planetarium shows suit most ages but can run long for very young children.