For a summer beach vacation, Xiachuan offers a small but modern beach town with prices 1/3 that of Hainan. You can play on the surf, scuba dive, parasail, jetski and rent 2/3/4 seat bikes. The cost is ¥94 for a roundtrip boat ride, ¥20 for the on-island bus ride and ¥40 for the resort entrance fee. Buying a full package from a travel agent should give you ¥20 discount and save on time in waiting in lines. Hotels there start at ¥150 away from the beach (although at most a few minutes walk) and can go up to ¥800 during peak periods. Food is expensive (for Taishan) at the resort so before entering the resort -- or after leaving it -- hit the local towns for delicious, fresh and cheap seafood.
"Water Tower", 水中碉楼 Shuǐzhōng Diāolóu
Nearby Kaiping is famous for its diaolou watchtowers built in the early 20th century by overseas Chinese, but Taishan has quite a few as well. This one was flooded when a reservoir was constructed, leaving only the top few stories sticking out of the water. Nearby is a village that was spared from flooding, where the cows still graze on the sloping side of the dam.
台山博物馆
台山市华侨文化博物馆
Large modern museum with exhibitions on the many Chinese people who migrated overseas from Taishan.