There are about fourteen, variously crumbling, Cham towers still standing upright in Binh Dinh province -- the only thing that makes Thap Doi (twin towers) different is that they are easy to visit from the city centre.
They're good examples of the Cham architectural style, if you haven't seen it before, and the grounds are well-tended with a pretty garden.
To get here, head west on Tran Hung Dao, past the new bridge, and keep your eyes peeled for a right hand turn 2 km down. The street is unmarked, but it's the most promising of the right turns you'll find, and there is a very small sign which is only visible if you are coming from the other direction. Luckily it's one site the locals all know and by shouting, Thap Doi, Thap Doi! over and over again, you'll get their fingers wagging in the right direction. A small admission fee is sometimes collected if someone is on site to collect it.