I was unsure what to expect when arriving at this hotel as all the hotels in Cartagena seem lovely in photos on the internet and this hotel was very reasonably priced for its location. (We paid $176,000 pesos for a triple room, including buffet breakfast) However, we were quick to realise that this hotel was everything it claimed to be and more. A lovely change from the high rises all over Bocagrande, it is laid out over only one floor, nice and cool within and beautifully decorated. The rooms were very spacious with nice bathrooms, flat screen television with cable, minibar with very cheap prices ($2800 pesos for a beer) and powerful airconditioning which you can adjust to suit you. The best thing for us was the staff who were very helpful and so friendly. They gave us the latest check-out they could manage as our flight left late at night, kept our bags behind the desk until 9pm. We kept our valuables in the safe at reception and had no problems with that. The receptionist booked us a trip to the Islas Rosario with a discount unmatched by any other operator that we found in Cartagena. Even the touts by the docks acknowleged they couldn't beat it! Perhaps the only thing that would have made it better is having hot water, as we arrived in the rainy season and it wasn't really sunny at all. A good trick, though, that the receptionist mentioned is that at 12pm the water does in fact come out warm!
All in all, it was the best part of our holiday and I am thankful for the other reviewer here for recommending it, as that was the reason we finally chose this gem of a hotel.

I stayed at this beautiful hotel for four nights in early May 2008.
May 2-6. I stayed in room # 104, on the ground floor. Room had a big queen size bed and a single bed. This is a great little 40 room hotel, located on Cartagena's main road of San Martin Avenida. This hotel has been recently completely refurbished in the old Spanish colonial style. Great A.C. in the room. Fully stocked mini-bar with reasonable priced items. Room service is available, from a reasonably priced menu. A free breakfast buffett(which is hard to find at any other hotel in this town). They have a great big veranda slash side-walk cafe type sitting area on the front and side of the hotel, but no dining tables on the inside, so, I would imagine that inclement weather, you would carry your free breakfast buffett back to your room, in order to eat it. With the front of the hotel facing north, the sun, is constanly on the hotel, so, there is very little shaded areas. if they would add shades to the tables, that would help a lot. Or better yet, extend a roof over the entire area, in keeping with the arcaticture of the style of the building. The food was good, most Colombian food is nothing to get excited about. It's basic and filling. For you Gringo turistas, diagonally across the street is a Micky D's(McDonalds)(the only one in town) So, if you can't remember the address of the hotel, for the taxi driver, just tell him to take you to McDonald's. Directly across the street is another well know S.A. restaurant chain, Crapes & Waffles. But, it does not open until noon-time, until 11 P.M.
I rated this hotel as 3 stars. It does not have a swimming pool, but you are just a one block walk from the ocean. The ground floor rooms do not have windows that look outward of the building, but they do look inward, toward the small courtyards.
The biggest negative I found, was that they did not have individual room safes in the rooms. Security, is a big plus for me when I travel. The hotel was very secure and safe, but, I just like that extra benefit of having my own room safe.
The price of the rooms are from 132,000 COP(Colombian Peso)
( $ 73 U.S.D.) to 143,000 COP( $ 80 U.S.D.)
This is a great convient hotel, very well kept, and staffed, great maid service, they can arrange tours for you also. About half of the staff understands some English. Everybody was very helpful.
There was one other negative, this hotel does not have it's own web site(and it should). So, you have to book through a third party web site, which I really do not like, but, I took a chance.
And, the only reason that my booking went right to begin with, was that I was already in Cartagena(staying at another hotel), and, I went to this hotel to re-confirm my reservations. After a couple of hours of confusion, my reservations were confirmed.
I booked my stay at this hotel for when I returned to Cartagena, after my trip to Ecuador.
Please, Hotel San Martin, invest in your own web site, and add some room safes, and, you could add another half a star to your rating. I would definately return to this hotel on my next visit to Cartagena.
Free internet(one computer) in the lobby, for use by guests.