We stayed here for four nights at the end of our Costa Rican holiday, and it was a fantastic finish.
We stayed in a tropical suite, which is nice and spacious with a California King bed, a ceiling fan and AC and a Jacuzzi tub and a swimming pool with ocean view outside.
Be aware, that you will probably be only taking your meals here, since it is at least a 20 minute drive to another restaurant. The food is very good, but the selection is rather small.
We hiked to the waterfall, which was not as impressive as we had hoped (but this is the dry season, maybe when there is more water in the wet season it is better). The viewpoint is nice for sunsets.
The beach is nice - clean and quiet
Nature Highlight: the howler monkeys that roam behind the hotel

The hotel is an upmarket establishment situated on its own length of beach in the wilds of the Nicoya peninsular. The beach is about half a mile long and is truly spectacular in the early morning being palm fringed and usually virtually deserted. However one word of warning for sea lovers - it can be 'muy peligroso'. Waves can come in viciously, yet it is these very conditions that give the resort is character. Reception was good and we had chosen a standard room - highly recommended. This was both spacious and airy (with air conditioning) with a large balcony overlooking the ocean. Bathroom was equally spacious and came with quality toiletries. The room also benefited from a mini-bar and coffee making facilities. Food was good although somewhat pricey - a dinner for two with a base-line bottle of reasonable wine (2 courses) comes in at around USD 100. It should also be noted that when my wife required some changes to a dish (she does not eat dairy products) she was always accomodated. Lunch in the pool restaurant would be cheaper. The menu changed little from day to day but was wide enough to satisfy. Breakfast was good with the usual Costa Rican offerings plus an egg station. Pools were good with adequate sunbeds and beach towels are provided. There is a pool bar. WiFi is resort wide but at times can be patchy, but is free. The Belgian owner, Hilde, is a charming hostess who constantly enquires as to your comfort. A single mention to reception of a faulty shower brought immediate remediation. This is a rare establishment, being both of high quality as well as being well off the beaten track.

My wife and I stayed at Tango Mar for 5 nights during our 2 week honeymoon to Costa Rica. This place was just what we were looking for, slightly isolated, beautiful beyond belief and some of the nicest staff I have ever met. We had a ocean view from the third floor and loved waking up and falling asleep to the sound of the ocean. The beach is awesome, nice sand and fun waves to play in. The breakfast is included in the price and I was very happy with what they offer, the lunches and dinners were very delicious as well.
Hilda was such a nice person to come around every night and see how our day was, it's a very nice touch.
Go to the look out point for sunrise and have one of Javier's Long Island Ice Tea's!!

This is a gorgeous spot. The beach and pool are truly beautiful and it's hard not to enjoy yourself here. The tours and spa services offered are excellent, and overall the food is pretty good although a bit expensive. Service is spotty and I would say is the only downside. Some of the people working here are real gems but others don't seem to realize that if they treat people kindly, they will want to come back and tell their friends to come too.