I stayed at An'na Tham for 3 days as part of a tour of Vietnam. The hotel is simple, clean and adorable. It sits in the tiny village of Bich Dong, just outside of Tam Coc. The view from my balcony, breathtaking and Tham and her husband were lovely: really warm and friendly and when I had to get up at 6 for an early morning trip, Tham cooked me an omelette baguette.
I spent 2 of the days exploring: first the Mua caves, around 7km away by bike then Bird valley, around 5km in the other direction, through beautiful rice fields - and just next to the hotel were two cave temples - the whole experience was astonishing - just be prepared to do a fair bit of climbing steps.
If you are looking for a luxury tour then join the other drones who get ferried to the sites in air conditioned buses and whisked around by the tour guides, if you want to experience the beauty and warmth of this amazing country directly, stay at places like An'Na Tham hotel, hire a bike, seek out simple food and get exploring.