Na Phra Lan Tunnel Gate 1

Air conditioning, seating, charging points and clean free toilets, all underground and all for nothing. That's the pitch, and around the Grand Palace it's worth more than it sounds. This is a pedestrian tunnel linking street level to Sanam Phra Lan and the palace precinct, so you cross under the traffic instead of through it, but most people end up staying longer than the walk requires.

The hall is bigger than you'd guess from the entrance, well lit and signed, with wall displays and photographs about Bangkok's history running along it. Reviewers keep using the word museum, and while I'd not make a special trip for the panels, they're a genuinely pleasant thing to read while your shirt dries out. It works as a meeting point for groups, a place to sit after two hours on your feet at Wat Phra Kaew, and shelter when the afternoon rain arrives without warning.