Gulf of Nicoya it is, Ticomaya.
This picture is taken from a small amphitheatre at the hotel Vilas Caletas, which I highly recommend if you are ever on the Pacific side of Costa Rica. It sits 1000 feet up on a spur of land that juts into the golf. The sunsets are spectacular, and every evening people gather at the amphitheatre (conveniently just beside the bar) and watch while live or recorded music (usually big symphonic numbers) are being played from the amphitheatre's stage.
Thought the amphitheatre would throw everyone to guessing European locations .....
Hey, gus!