Guernsey's Victoria Tower has opened to the public again, after closing while emergency radio equipment was replaced.
The historic structure was closed in December so that the TETRA (Terrestrial Trunked Radio) system housed there could be updated after 10 years of use.
Sea Fisheries, the Guernsey Border Agency and the prison service are amongst those which make use of it.
Helen Glencross, the historic sites curator, said the tower provided an excellent view of the whole Bailiwick.
"When you get to the top, you're about 300ft (91m) above sea level, so you've got absolutely stunning views over town and over to Herm and Sark".
Those wanting to climb its 99 steps to enjoy the views from its balcony can get the key from Guernsey Museum.
The structure was built to celebrate a visit to the island by Queen Victoria and Prince Albert in August 1846.
There was enormous enthusiasm in Guernsey following the royal visit, as it was the first time that a reigning English monarch had set foot on the island.
A public subscription raised £2,000 to pay for the structure and yet it served no useful purpose, except to symbolise Guernsey's links with the English monarch.
Now however, more than 150 years after its completion, the communications equipment housed in the octagonal "lantern" at its top provides a crucial facility for the island's emergency services.