The big resorts of the Hotel Zone dominate Cancun's famous Caribbean-facing beach. All of Mexico's beaches are public property, so you can use the beach of any hotel by walking through the lobby or directly onto the sand. Be especially careful in the water of these east-facing beaches because they front the open Caribbean, where the undertow can be quite strong. By contrast, the waters of Bahía de Mujeres (Mujeres Bay), at the island's north end, are usually calm and ideal for swimming. Get to know Cancún's water-safety pennant system, and check the flag at any beach or hotel before entering the water. In the Caribbean, storms can arrive and conditions can change from safe to unsafe in a matter of minutes, so be alert: If you see dark clouds heading your way, make for the shore and wait until the storm passes.Playa Tortuga(Turtle Beach),Playa Langosta(Lobster Beach),Playa Linda(Pretty Beach), andPlaya Las Perlas(Beach of the Pearls) are some of the public beaches on the bay. The small but beautifulPlaya Caracol, by the Xcaret Terminal, also faces the bay's calm waters and, for that reason, is preferable to those facing the Caribbean.