Local historians want to put the Bognor Regis Museum on the map.
Visitor numbers to the attraction in its current premises have halved compared to last year.
May saw just over 800 people take advantage of its free entry from 10am to 4pm Tuesdays to Sundays and bank holidays.
The local history society members who run the facility fear many people are unaware of its location of the past two months on West Street.
The only sign in the town which gives directions to the museum still points from the seafront along Norfolk Street to the previous building on the High Street.
It needs to be moved some 370 yards westwards.
Kay Fall, the chairman of Bognor Regis Local History Society, said: “We are desperate for a new sign.
“We are only getting about half the numbers we used to.”
She added: “What we want is to have the sign moved a few hundred yards on the promenade to point down West Street to our new building.
“We have put a map in the window of our old museum to tell anyone who goes there how to get to us.
“But we need people to be easily able to find out where we are.
“We asked the county council to move the one sign we have soon after we moved premises.
“We are still waiting for something to happen.”
A county council spokeswoman said: “We are aware of the need to move the museum road sign and this should be carried out in the near future.”