Entrance to one of the water grotto....
Inside the grotto....the cave ceiling just touching your head....
the exit and continuing journey....
local tourist also taking the weekend break to relax... 
at this point.. there are still 1 hour 30 minute more to go. Most of the boatman and women, old. So if you kind enough, just give generous tips.
The journey start around 830am, reach there 2 hour plus later. The boat ride will be around 2 hours. But I bet you won't notice the time passing by. There's additional visit to the historical temple. I advise you to bring along hat as the sun is scorching hot... 
For foreigh tourist, the boat operator only allow 2 person per boat.... so bring your partner along. I have no partner that day, so I have to wait .... Tam Coc - Bich Dong (Vietnamese: Tam Cốc - Bích Động) is a popular tourist destination near the city of Ninh Binh in northern Vietnam.
The Tam Coc (“three caves”) portion is a three-hour excursion by small boat along the Ngo Dong river, beginning at the village of Van Lam and proceeding through a scenic landscape dominated by rice fields and karst towers. The route includes floating through three natural caves (Hang Ca, Hang Hai, and Hang Ba), the largest of which is 125m long with its ceiling about 2m high above the water. The boats are typically rowed by one or two local women who also sell embroidered goods.
Bich Dong is a pagoda on nearby Ngu Nhac Mountain dating to 1428, comprising three structures: Ha, Trung, and Thuong Pagodas, in ascending order. Guided tours generally cover historical points and end with a pleasant view from the top.
The boat crusing the local village along the river.
Natural washing machine...
Cyling the boat oars... a rare talent... 
