Hundreds of people got the chance to step back in time yesterday as Shire Hall Historic Courthouse Museum opened its doors to the public.

The project to transform the building into an interactive museum, giving visitors a first-hand experience of what it would have been like to walk through the cells and into the dock, has taken four years.

A queue of people formed outside ahead of the 10am opening as people tried to be first through the door to claim a year’s worth of free coffee. The next 99 people were also given a free coffee to enjoy at the museum’s new café, which is run by Kingston Maurward College, Dorchester. The café is free to visit, as is the new gift shop.

Gail Aldwin, from Dorchester, aged 56, was the lucky person to receive a year of free coffee, she waited from 7am on a chair outside in the sunshine. She is a crime author and will be giving crime writing workshops in the autumn at Shire Hall.

She said: "I live on Glyde Path Road and I'm a writer so I thought it would be a unique experience to come down and watch the world go by for a couple of hours. I think it's really exciting.

“It will be an asset to the town and it's great to have an opportunity to think about the Tolpuddle Martyrs and their experiences. I came around on the hard hat tour, so I saw it in development."

The new immersive museum celebrates social justice and looks at the history of protest both in Dorset and in the wider world. Its restoration was made possible thanks to a £1.5m grant from the Heritage Lottery Fund, which was match-funded by West Dorset District Council. The museum is a registered charity run by the Shire Hall Trust.

One of the first exhibitions will be about protest, including the US Civil Rights Movement and Dorset’s history of protest. The local history part was researched and designed by young people in Dorset, working with Shire Hall staff and the Dorset History Centre.

Director at Shire Hall, Anna Bright, said she was delighted to see the museum open to the public.

She said: “The opening today marks the culmination of four years of work to bring this unique new attraction to Dorchester. We would like to thank West Dorset District Council and the Heritage Lottery Fund for their support. We hope this will be a place that local people and tourists alike will be able to enjoy over and over again – each time they visit learning something new about the justice system, the fight for social justice and the nature of the human spirit.”

The museum opened on International Workers Day – very apt considering the Tolpuddle Martyrs were tried and sentenced there – the outcry it sparked jump-starting what would become the modern trade union movement.

Anita Pegorini, 72, from Dorchester came down to visit with her daughter Marie Chappell, 38. Anita said: “It was so interesting. It’s an added attraction for the town.”

Marie said: “Having this open, they have added to the history of Dorchester.”

The museum is open every day from 10am to 5pm. Entry is £8.50 for adults, £4.50 for children and £20 for a family, this includes an annual season ticket giving visitors unlimited free returns for a year.

For more information visit shirehalldorset.org