Visit Hoa Lu and Tam Coc and learn more about the northern Vietnamese countryside, history, and culture on a full-day tour. Hoa Lu is an ancient capital, and Tam Coc, which means “3 caves,” features karst formations and caves you’ll explore by boat.isit Hoa Lu and Tam Coc and learn more about the northern Vietnamese countryside, history, and culture on a full-day tour. Hoa Lu is an ancient capital, and Tam Coc, which means “3 caves,” features karst formations and caves you’ll explore by boat.