BARANGAY SANTISIMA TRINIDAD
Stma. Trinidad is a barrio located in the northerly most part of the town of Malolos. It is almost five kilometers from the town proper. It is bounded in the east by Barangay Barihan, in the south by Sumapa, in the west by Pinagbakahan and in the north by Lagundi, Plaridel and Lugam Malolos. This historic Barrio existed during the Spanish era. The barrio was named Stma. Trinidad in the honor of their Patron, the three persons of the Blessed Trinity. According to the elders of the Barrio the image or the picture of the Blessed Trinity was found in a rice field being plowed by a farmer exactly where their chapel stands at the present. With the collective effort of the people of Pinagbakahan, Barihan and Stma. Trinidad, they erected their community chapel and there they enshrined the image of the Blessed Trinity. In the back the image picture is written the date January 19, 1500 at present it is clear and readable, and the picture of God the Father the son and the Holy Spirit remains also very clear and bright. In those days the early settlers of the barrio are the Valerios, Valenzuelas, Manahans, Santiagos, Dela Cruzes, Surios and Roques. From the barrio of Stma. Trinidad came out as the separate barrios. Pinagbakahan and Barihan.
According to the elderly folk, not too long after the construction of the chapel, there was discovered a deep well beside it and out of this came a very cold and crystal clear water. Also according to those living near the chapel the water is a cure to any kind of sickness, once you drink or bath from it. It is so effective in all sickness provided you profess your full trust and faith to the Blessed Trinity. It became well known natively in Bulacan but in Manila and nearly provinces so they go on pilgrimage to this barrio. The sites of Pinagbakahan, Barihan and Stma. Trinidad has only one common chapel and patron of them is the Blessed Trinity. According to accounts there are 883 and 5,129 population of three sites. Their people engage in farming employment and home industries for their livelihood.
6,111 as of 2007 Source: NSO Census of Population, 2007