The Roundhouse had been unused for years
Visitors have been given a one-day only chance to preview the £48m restoration of Derby's historic Roundhouse ahead of its official opening next month.
Derby College officials opened the doors after receiving a large number of requests from local people.
The former steam engine workshop has been converted into a college campus where about 2,500 students will start their studies this month.
The Pride Park site opens as a visitor centre at the end of October.
The historic Roundhouse project saw the Grade II and Grade II* listed buildings on the site refurbished to form the new campus hub.
The Roundhouse is though to be the world's oldest steam engine workshop, but it had remained unused for many years.
Vice Principal Steve Logan said: "We have had a large number of people calling us and turning up at the Roundhouse desperate to see the restoration for themselves, and therefore decided to open the doors for one day only at this time to showcase the breathtaking restoration of this magnificent building.
"Students will be arriving for the start of term the following week and we are in the midst of enrolment but recognised that it was important to hold this event sooner rather than later before the Roundhouse officially opens as a visitor hub at the end of October."
Last month students were given a preview of the new facilities, where studies in engineering, business, plumbing, art and design and catering and hospitality will be based.