Tonga is of four main island groups, Tongatapu in the south, Ha'apai, Vava'u, and the Niuas in the far north. The kingdom's 170 islands are sprinkled over 700,000 square kilometers of ocean. 
     Carbon dating confirms that Tonga has been inhabited since 1100 BC but many scholars believe the first settlers of Polynesia came to Tonga about 3000 BC. The ancestry of King Taufa'ahau Tupou IV can be traced back to the ancient Tu'i Tonga, Tu'i Ha'atakalaua and Tu'i Kanokupolu line of kings. Today the Kingdom of Tonga is a constitutional monarchy. 
     In 1781 Spaniard Francisco Antonia Mourelle, on La Princesa, was the first western explorer to sight the Vava'u island of Tonga. Mourelle named its harbor “Port of Refuge.” The group's tiny capital Neiafu is perched above Port of Refuge Harbor, unquestionably one of the most beautiful natural harbors in the world. 
     The stamp from Tonga celebrates the bicentenary of the discovery of Vava’u in 1781. The map is identified as Plano del Fundadero de Refugio y Puerto Valdes, 1793. There is no indication who drew the map.