45 minutes from Bacalar, this Mayan archeolgical site is a great spot to see Mayan pyramids and ceremonial site. You may have the site to yourself or share it with a small number of other visitors. It is on the south side of the highway heading towards Escarcega. There are two other archeological sites near it, Dzibanche, and Kinichna. They are access on the north side of the same highway and are also about 40 minutes from Bacalar.
The Bacalar Lagoon, is a fresh water lagoon, 60 km long. It is also known as the Lagoon of Seven Colors for its different shades of blue and turquoise. The depth varies from a meter or so to over 90 meters in the sink holes ( there are three in the lagoon). There are many tours operators offering tours including from the wedding venue. If you have a group you can ask for a personalized tour, stopping whenever you feel like it to take a swim. The standard tours takes you to two cenotes, a swimming stop and the " pirate canal". You will also see the stromatolites, an ancient life form still alive in the lagoon. Both sail boat and motor boat tours are available.