Rio Maior is the seat of a municipality with an area of ??272.76 km² and 21 192 inhabitants (2011), subdivided into 10 parishes. The municipality is limited to the north by the municipality of Porto de Mós, to the northeast and to the south by that of Santarém, to the south by that of Azambuja, to the west by Cadaval and to that of Caldas da Rainha and to the northwest by Alcobaça.
The Municipality of Rio Maior, in the district of Santarém, is part of the Sub-region of Lezíria do Tejo and in terms of tourism it is part of Turismo do Alentejo and Ribatejo. Its main natural points are Serra dos Candeeiros and Rio Maior, a tributary of the Tagus. In a surface of about 270 km2 are the mountain landscape and the area of ??Bairro Ribatejano, a privileged space between the Vale do Tejo Region and the West Coast of Portugal.
The several water lines that run through its territory constitute a dense hydrographic network, of which the Greater River stands out, which gave its name to the town and municipality.
The north of the municipality, bounded by the Serra dos Candeeiros and integrated into the Natural Park of Serras D´Aire e Candeeiros, presents a varied number of caves and natural algars. To the south, the plains and, consequently, the Ribatejo influences are more evident.
The Municipality offers its visitors a variety of cultural, gastronomic, contact with nature and also sports options.
The tourist potential of the municipality is, above all, associated with the rural character of his past experience and his integration in the Serras d'Aire e Candeeiros Natural Park, where sometimes the cultural and the environmental are combined in an exemplary way.
3 km from the city of Rio Maior you can find the natural salt flats of Rio Maior.