Places in Middle-earth
Ondosto A place in the Forostar (Northlands) of Númenor, probably particularly associated with the stone-quarries of the region (Quenya ondo 'stone').
Unfinished Tales, Index
The chief and most ancient road suitable for wheels... was early extended [from the Meneltarma] to Ondosto within the borders of the Forostar, and thence to Andúnië in the west. Along it passed wains bearing stone from the Northlands that was most esteemed for building, and timber in which the Westlands were rich.
Unfinished Tales, Part 2, Ch 1, Description of the Island of Númenor
gond 'stone' in Gondolin, Gondor, Gonnhirrim, Argonath, seregon. The name of the hidden city of King Turgon was devised by him in Quenya as Ondolindë (Quenya ondo= Sindarin gond, and lindë 'singing, song'); but it was known always in legend in the Sindarin form Gondolin, which was probably interpreted as gond-dolen 'Hidden Rock'.
The Silmarillion, Appendix: Elements in Quenya and Sindarin Names
Contributors: Elena Tiriel 6Feb10