The only visible features still on the site are the ruined tower house as well as a small nearby motte.[6] The castle, its motte and the remnants of a nearby bailey (courtyard) are listed on the Record of Monuments and Places for County Westmeath.[7]
^ abOrpen, Goddard H (1910). "The Mote of Castlelost, County Westmeath". The Journal of the Royal Society of Antiquaries of Ireland. 40 (3). Royal Society of Antiquaries of Ireland: 226–228. JSTOR25514078.
^Kelly, Jennifer A (1997). Richard Tyrrell: Elizabethan Captain. Tyrrellspass Development Association. pp. 10–12. Castlelost would appear to have been the family headquarters in the sixteenth century
^Lewis, Samuel (1837). Castlelost. Lewis. [In Castlelost] are still remaining some ruins of the old castle, and of an ancient mansion-house, which were for successive ages the residences of the Tyrrell family, whose possessions were forfeited in the war of 1641{{cite book}}: |work= ignored (help)
^Brewer, James N (1826). The Beauties of Ireland: Being Original Delineations, Topographical, Historical, and Biographical, of Each County, Volume 2. Sherwood, Jones, & Company. p. 252. At Castle-Lost [..] we find the ruins of a castle, of a mansion-house, and a church [..] This castle, and the adjoining mansion, long afforded a residence to the Tyrrel family [..] The Castle-Lost estates were forfeited by the Tyrrel family, in the troubles of the seventeenth century
^McElherron, Brian T (2016). "Castlelost". Irishantiquities.bravehost.com. Retrieved 25 August 2019.