The canals that branch off the Chao Phraya into Thonburi represent old Bangkok more faithfully than anything on the tourist circuit. Hiring a longtail boat from the Tha Chang or Tha Tien piers for a private hour or two on Khlong Bangkok Noi and its tributaries passes through canal-side communities, Buddhist temples with no tourist infrastructure, flower markets, and river villages that feel entirely removed from the city visible from the main thoroughfares.
The best time is early morning, before the heat and before the canal traffic picks up. Negotiating a price is straightforward — most boatmen understand the standard tourist routes and will take you anywhere you point on a map. The sound and smell of a longtail engine on a narrow klong at dawn is one of the characteristic Bangkok experiences.