The large estate, with its focal point the "Big Hoose", played an integral role in the social and economic life of Buchan until well into the 20th century. Financial considerations, however, have resulted in many estates being sub-divided to be sold in small units and several Big Hooses have been demolished or allowed to become ruinous because the owners have been unable to meet the costs of maintenance.
(Jim Buchan, Bygone Buchan)

Aden Country Park is based around the ruins and steadings of Aden House, built in ???? it was the home of the Russell family until 1937. At its peak Aden Estate covered 31 square miles.

The steadings house the Aberdeenshire Farming museum and Heritage Centre. Here you can get a feel for life as a worker on an estate farm, in the ‘Big House’, or as one of the estate tradesmen. Perhaps this was how your ancestors lived?

Aden was one of several big houses built in the 18th and 19th century.
Rattray House:
an 18th century Regency building, privately owned
Crimonmogate:
built in 1825 by Archibald Simpson, now available for weddings and corporate entertainment:

Craigellie House:
1840-1, architect John Smith. An Italianate masion privaltey owned
Strichen House:
1818-21 also designed by John Smith for one of the Fraser family now in ruins:

Cortes House:
Early 19th century Regency villa built for the Gordons of Cairnblug. Now Self-catering accommodation.

Cairness House:
Built of Charles Gorden of Buthlaw in 1791-7 by James Playfair. This is arguably the finest neo classical mansion in Scotland. Now in the process of being restored it is open to the public:

Pitfour Estate:
was one of the great estates of North East Scotland. The house dubbed ‘The Blenheim of Buchan’ was built in the early 18th century for the Ferguson family. Sadly it was demolished in 1927. However you can still see evidence of the Ferguson’s extravigent lifestyle that was typical of most of the Buchan lairds in the 1850’s. Pitfour Loch was created for the opportunity to build a substantial bridge.

The boat house was constructed to look like a ruin and the Temple of Theseus on the edge of the loch was a bathing place and said to also contain Admiral Ferguson’s alligators! Pitfour Loch is now a trout fishery. In Drinnies wood overlooking the estate, an Observatory (pictured below) was built in 1845 by Admiral Ferguson. It is said that the Admiral erected the tower to watch his stables as his horses practiced for races. Whatever it was built for, it now offers an amazing view of Buchan for miles in every direction. You can also follow the course of the unfinished canal planned to link the estate to the sea.

Above - Pitfour's Temple of Theseus: Below - how it looks today: