Portobelo. Legend has it that Columbus named Portobelo as soon as he saw it. The color of its deep blue sea, the white of its beaches, along with the intense green of its forests and mangroves, deserve no other name.the ruins of a Spanish castle and its old cannons. The group of forts that once defended the town from pirate attacks has been declared a UNESCO World Heritage Site. Among its narrow streets and brightly painted houses, you'll find restaurants with exquisite Afro-Caribbean cuisine.