Santurce is a barrio of San Juan. Its population in 2020 was 69,469. It is also the biggest and most populated of all the barrios in the capital city with a bigger population than most municipalities of Puerto Rico and one of the most densely populated areas of the island .

Santurtzi is a port town in the province of Biscay, in the autonomous community of Basque Country, Spain. It is located in the Bilbao Abra bay, near the mouth of the Nervión river, on its left bank, 14 km downriver from Bilbao and forms part of the Greater Bilbao agglomeration. It has a population of 45,853 (2019) and a land area of 6.77 km2.