Our hotel helped us book the Hoa Lu-Tam Coc for about USD40. We were picked up from our hotel at 8am and were lucky enough to have a small group of 12 on the tour. Our guide, Trung informed us of the schedule for the day, and we set out for a three hour drive out to the country on a minibus.
We visited the Hoa Lu ancient capital (which was the first capital of Vietnam) and the temples around the area, dedicated to the emperors from the Le dynasty and the Le Dynasty. Our guide Trung was a fantastic storyteller and historian, always ever ready to answer the questions we had about the place. The temple grounds themselves were interesting and serene.
We stopped by for buffet lunch at Tam Coc (seems like all the tour groups stop by the same restaurant), which was about average. Vegetarian options limited, drinks extra.
We then made our way to the Tam Coc wharf and had a leisurely two hour row through the caves and the river. The locals (mostly women) row with their feet, and the landscape through the limestone caves were pretty gorgeous, although two hours might be a bit too long for some (dad was starting to doze off on the boat). It was also good that the tour limited us to only two people to a sampan - I saw other boats carrying four or more, which seemed like a bit much for the poor rower!
At the end of the limestone caves there were several boats with wares to sell, mostly snacks and drinks. Make sure you buy a drink for the the rower, it's definitely hard work (I tried to row the boat for a bit - only managed a few minutes before we almost hit the banks!)
After the boat ride, we had a cycle through the local town up to the paddy fields. They provided us with some old bicycles (mine was a bit on the tall side). Road was bumpy at times, and hard at times - definitely not for those not used to cycling! It was lovely and scenic though to cycle through paddy fields with the limestone mountains in the background. It took us a good hour to cycle through and end up back to our starting point beside the lake.
Overall I did enjoy the tour. I would have liked the option for a bit more commentary around Tam Coc, as the tour guide was not able to come with us to the boat, so we didn't really do much except enjoy the scenery. Also the bike ride might not be for everyone, so an alternative activity for those who were not going on the bike ride might have been a nice option - but since I was fit and able to do that activity I enjoyed myself thoroughly.