The ribbon has been cut at the newly-restored "jewel" in Northampton's heritage ahead of its official public opening tomorrow.
More than 100 volunteers, townsfolk and dignitaries turned out to see the grand opening of Delapre Abbey today following a three-year restoration.
From tomorrow, visitors will be able to access 60 per cent more of the former mansion and grounds, once home to a medieval monastery.
The hands-on attraction has now been split into different zones celebrating periods in its history, complete with an area dedicated to the Battle of Northampton, which saw King Henry VI captured by the Yorkists.
Speaking before cutting the ribbon to the abbey today, leader of Northampton Borough Council, Councillor Jonathan Nunn, described it as a "jewel in the town's heritage."
He said: "Today marks the day the whole building becomes open for a tour to the public - and I don't think the place has ever been in a better shape.
"In fact, in its 900 years of history, I don't think it has ever been in this tip-top condition.
"People from the town and everyone around love this place - and for the first time people can access all of it."
Television presenter and property developer Sarah Beeny cut the ribbon by paying tribute to "custodians of heritage" across the country.
"I think being here is a very inspiring thing to see," she said. "What I am particularly inspired with is how many people have worked together for this to have happened."
The restored abbey will have an interactive feel, free of ropes prohibiting access, the Delapre Abbey Preservation Trust claims "you can sit in any chair and touch anything."
The project was funded through a £3.65 million grant from the Heritage Lottery Fund and more than £3.5 million from Northampton Borough Council.
Director of the trust, Rachael O'Connor-Boyd, said the abbey's 150-or-so volunteers would continue to be a big part of the visitor experience, before announcing an "engaging" program of events from "Peter Rabbit trails to Rachmaninov recitals".
"This is a building we can be truly proud of," she added.
Ex-county council leader, Jim Harker, now the regional chair of the Heritage Lottery Fund, said a project with this level of finding "had to be very good".
And addressing the crowd today, he said: "My God it is."