Formed in 1995, Celtica provided domestic and foreign tourists with information on Celtic life through detailed dioramas of a round-house village, the opening times were 10am - 6pm.

Celtica Guest Centre was first developed by the District Council of Montgomeryshire, who took over Plas Machynlleth for the project.

Figures of men, women, children, and animals were placed around a dimly lit round-house village, which was built within a purpose-built extension to the Plas.

The centre attracted tourists, school groups, and conferences; however, initial visitor number predictions proved to be too ambitious and the council was unwilling to prolong its subsidy after years of consistent budget deficits.

[4] With little scope for alternative investment, Celtica closed in March 2006,[5] and the house stood empty while Powys County Council sought to relinquish responsibility for it in line with their policy of selling many of their publicly owned assets.