Enjoy swimming and relaxing at its marvelous ponds, created by the falling water. Erawan Waterfall flowing with emerald water is the major attraction of the national park. It is 7 tiered and spans over 1.5 km, each tier has also number of smaller falls into ponds full of fishes. A series of trails and footbridged will lead visitors all way up to 6th tier, last tear is accessible by scrambling up to few cliffs for those who like a bit more challenge. Most tears are running into ponds, great for swimming. There are few picnic spots around the lower tiers, food is strickly forbidden beyond the second tier.
The bridge over the Mae Klong (or Kwai Yai, or whatever) really was part of the death railway, built with prisoner and slave labor by the Japanese during World War II. There were actually two bridges built over the river here. A wooden bridge like you see built in the movie (which was actually shot in Sri Lanka) was built first about 100 meters up-river from the current bridge to expedite construction on the line beyond the river. The concrete and steel "main" bridge was added during the war when the steel became available.
Both bridges were bombed by allied planes near the end of the war. The squarish center spans of the bridge are post-war replacements. The wooden bridge was demolished after the war since its thick structure blocked the flow of the river.