The lighthouse is located about 1 km north of the center of Mērsrags, in a camping area.
In 1873, the Riga Stock Exchange Committee asked the Hydrographic Service of the Ministry of Maritime Affairs in St. Petersburg to install Mērsrags Lighthouse as soon as possible, because the rocky shore endangered ships that had deviated from the lines between the Kolka fire ship and the Daugava estuary. All the expenses related to the larger installation, the metal tower, the lantern and the optical apparatus were provided by the Riga Stock Exchange Committee meeting and bought in Paris. The lighthouse was consecrated on September 10, 1875.
The height of the lighthouse is 21.3 m high. The lighthouse tower was made at the Sotera, Lemonje & Co factory in Paris. That is why, as a small connection to Paris, Mersrags lighthouse is called "French lady".
The light rooms are crowned by a domed roof structure, which ends with a spherical decorative structure and a windshield. In 1975, a memorial plaque was erected at the entrance to the lighthouse in honor of the lighthouse's centenary with the years "1875-1975".
The lighthouse of Mērsrags is also immortalized in the postage stamp issued by SJSC "Latvijas pasts" in 2006. The mark shows the lighthouse of Mērsrags, with a cloudy sky in the background.
In 2019, celebrating for the first time the World Maritime Navigation Technical Day, on July 1, three lighthouses were opened for free inspection in Latvia. One of them, Mērsrags lighthouse. On this day, 108 people visited Mērsrags lighthouse. The youngest used these promotions was a 4-year-old boy with his family, and the oldest, a lady 83 years old.