A couple of interesting finds on Wikipedia:

“Conolly’s Folly is an obelisk structure and National Monument located near Maynooth, County Kildare, Ireland. The folly was built within Castletown Estate (containing Castletown House), which contains two follies, both commissioned by Katherine Conolly, the philanthropic widow of Speaker William Conolly, to provide employment for hundreds of the poor of Celbridge when the famine of 1740–41 was at its worst.”

“The Wonderful Barn is a corkscrew-shaped building on the edge of Castletown House Estate, formerly of the Conolly family, in Celbridge, County Kildare, Ireland. The barn itself is formally in neighbouring Leixlip. Flanked by two smaller dovecote towers, the barn was built with the stairs ascending around the exterior of the building. The barn was built in 1743 on the Leixlip side of the Castletown Estate.

“Several purposes are suggested for the unique structure:

“One theory is based on the custom in Georgian times of using doves as a delicacy when other game or animals were not in season, and suggest its use as a dovecote.

“The height of the structure would also lend itself to sport shooting, supporting another theory of its use as a shooting or gamekeepers tower.

“The tower is seen from the east windows of Castletown House, so it filled that vista, possibly as a folly.

“However, a central hole through each of the floors supports the generally accepted theory of its use as a granary. The barn was built in the years immediately following the famine of 1740-41, as there was a need for new grain stores in case of another famine. The Conollys owned Kilmacredock and rented it out, so the barn was also useful for their tenants.”