In the heart of the Colonial Quarter, right opposite the Mexican Embassy, though not easy to find if driving. Looks nothing special from the outside, but it is a little oasis inside, Lovely Moorish courtyard, insulated from Santo Domingo noise and bustle, where all meals are served. Small hotel car park directly opposite the main door was invaluable, and is always manned. Breakfast adequate, not special. Our room was a good size, with sitting area and well-fitted (and lit) bathroom. Bed and pillows were very comfortable. Walking distance to a range of restaurants, and though the streets are dark at night, it felt very safe.
Unless you have specific interests, Santo Domingo is not worth more than 2 days in our view. If we go back to SD this is where we would stay.