In 1924, the Municipal Council of the City of Split has issued a decision on the construction of the City Meteorological Observatory on Prvi vrh of Marjan. Engineer Erald Marchi, whose instructions were followed by the famous Czech architect Josip Kodl during construction, was appointed director. Meteorological observations on Marjan started on 1 January 1926, and daily reporting started in 1927. Before World War II, there was a semaphore signalling system used daily from the observatory building to inform the artillery battery on Sustipan, where a cannon would fire to signalise when it was noon.
Today, it is one of the most important weather observing stations in the Republic of Croatia.