The museum was opened in 1989, as a tribute to the priest Mr Ramón María Aller Ulloa, who was a renowned astronomer and mathematic born in Lalín in 1878 and died in 1966. The old residency of the scientist was adapted for the museum. The old building from the 19th century was the first space observatory of Galicia. The office, furniture and instruments that Aller Ulloa used for his works are preserved, as well as the documents, photographs and many books from his personal library.

In 2011 the recovery works started for this first observatory. The recovery included a new telescope (to offer night watches) and the remodelling of the old dome, restoring and reusing the original wood.

On the other side, the museum is devoted to two other distinguished personalities from Lalín: Joaquín Loriga e Laxeiro.

From Joaquín Loriga (Lalín 1895 Madrid 1927) forefather of Spanish aviation, the museum houses a permanent collection of his belongings. The painter Xosé Otero Abeledo, Laxeiro (Lalín 1908- Vigo 1996) was one of the unequalled personalities of Galician painting during the 20th century. Laxeiro donated the 37 works on display for the museum.

Since 1993, the hall for temporary exhibition hosts the International Biennial Pinto Laxeiro in odd-numbered years. The hall also houses temporary exhibitions, book presentations, concerts, conferences or audio-visual viewings.