Sketches and prints of the Darnley Mausoleum which is located in Cobham Woods, Kent. Designed by James Wyatt in 1808. Built for the Third Earl of Darnley, it does not appear to be related to the Lord Darnley who married Mary Queen of Scots.

Designs for the Darnley Mausoleum, erected in Cobham Park, Kent by the 4th Earl of Darnley. James Wyatt, architect. A copy of this colored drawing was presented to the Royal Academy in 1783. Image in the public domain due to age. https://commons.wikimedia.org/wiki/File:1783DarnleyMausoleum.JPG
Design for a mausoleum for the Darnley family, Cobham Hall, Kent: perspective, 1786. English. Architectural design. Pen with black ink and coloured (now faded out) washes within artist’s wash-line border on wove paper. James Wyatt, architect/designer (1746-1813). Collections of the Royal Academy of Art. Image © Photo: Royal Academy of Arts, London. Photographer: Prudence Cuming Associates Limited. Artwork itself in the public domain due to age. https://www.royalacademy.org.uk/art-artists/work-of-art/design-for-mausoleum-for-the-darnley-family-cobham-hall-kent-perspective

Ld. Darnley’s Mausoleum in Cobham Park.https://fiftywordsforsnow.com/ebooks/medway/

Very expensive. Supposed to have cost 10,000 £ in 1808 money.