Meet your guide in the morning at the bike shop in Bangkok to be outfitted with your high-quality mountain bike and helmet. After a safety briefing, cross the Chao Phraya River by ferry, and bike along quiet back roads to reach the train station.
Enjoy the scenery that rolls by the train windows during the 1-hour journey to the coastal town of Mahachai. Upon arrival, check out the local market, which sits within arm's reach of the train tracks and is one of the largest traditional fresh-seafood markets in Thailand.
Then take another ferry across the Tha Chin River, hopping back on your bike afterward. Before long, you’ll hit the beginning of some seriously fun cycling tracks. Follow your guide down dirt roads that take you past mangrove forests, shrimp farms and salt ponds along the sparkling Gulf of Thailand. Look for wildlife such as kingfisher birds and water monitors, large lizards that can measure up to 6.5 feet (2 meters) in length. You may also even spot the small but impressive mudskipper fish, which has adapted to living mostly on land.
Stop for a seafood lunch at a waterside restaurant, and then continue along the gulf shore to a mangrove conservation center, where you'll learn about local ecology. Take in a bit more of the beautiful countryside and coastline before returning to Bangkok by train and ending your day trip back at the starting point.
Expect to ride a total of about 32 miles (52 km) at a leisurely pace, with frequent stops for water breaks and photo ops. Drinking water and snacks are provided throughout the day. In Bangkok, you’ll ride through alleyways, away from the big roads; along the gulf, you’ll take quiet, flat country roads. The tour is not recommended for novice cyclists. You must be able to carry your bike on and off the train and over footbridges at times.