Full Report for Listed Buildings
The list description is not intended to be a complete inventory of what is listed: it is principally intended to aid identification. By law, the definition of a listed building includes the entire building (i) and any structure or object that is fixed to the said building and ancillary to it and (ii) any other structure or object that forms part of the land and has done so since before 1 July 1948, and was within the curtilage of the building, and ancillary to it, on the date on which said building was first included in the list, or on 1 January 1969, whichever was later.
Summary Description
Reference Number
22860
Building Number
Grade
II
Status
Designated
Date of Designation
25/02/2000
Date of Amendment
25/02/2000
Name of Property
Grotto in Gnoll Estate
Address
Location
Unitary Authority
Neath Port Talbot
Community
Tonna
Town
Locality
Gnoll Estate
Easting
278044
Northing
198090
Street Side
Location
At the NE end of the Gnoll Estate on the hillside immediately W of the informal cascade.
Description
Broad Class
Gardens, Parks and Urban Spaces
Period
History
The extensive park and grounds at the Gnoll were laid out for Sir Humphrey Mackworth in 1724-7 and were centred upon fish ponds (that also supplied water to his copper works) and cascades. An informal upper cascade in Mosshouse Wood was added in the 1740s by an unknown designer, working for Herbert Mackworth. The grotto beside the cascade was also added at this time. Follies were later added in the 1780s by Sir Herbert Mackworth, which included a gazebo above the grotto and the Ivy Tower. The late C18 was the heyday of the Gnoll grounds, although it was revived in the C19 by the Grant family and Charles Evan Thomas. The latter came to an agreement with Neath Corporation for the building of Mosshouse Wood reservoir, which is dated 1889. The estate was acquired by the local authority in 1923. The house was demolished in 1957. Restoration of the grounds began in 1984-5 when the grotto was rediscovered.
Exterior
Cut into bedrock beneath a rebuilt gazebo. The entrance has a large bedrock lintel and is flanked by drystone revetment walls, the whole composition intended to resemble a Cotswold-Severn style prehistoric chamber tomb. Inside, the single circular chamber is quarried out of bedrock and has a crude flattened domical stone vault, which was intended to drip lime and form stalactites. The floor has an outer circular pavement of random paving stones and a kerb, which probably defines a former pool in the centre.
Interior
Reason for designation
Listed as an unusual and well-preserved feature of an important landscape garden, and for group value with the adjacent cascade.
Cadw : Full Report for Listed Buildings [ Records 1 of 1 ]
Export