Castell de Sant Nicolau is an octagonal fortress tower constructed between 1680 and 1682 in the port of Ciutadella de Menorca, built from marès stone by architect Josep Castellón. The truncated pyramid structure with a vault-formed interior originally served as a lookout and supply storage against maritime attacks, featuring a spiral staircase connecting to an observation terrace. Named after a hermitage that previously occupied the site, the castle now belongs to the Municipality of Ciutadella and offers free access, providing panoramic Mediterranean views and insights into Menorca's maritime defensive heritage.
