Of course, you will not find them using Google maps if you do not have a proper present name of the location. http://lazarus.elte.hu/hun/maps/1910/
No location in old Hungary starting with Hernat but HERNAD:http://www.radixindex.com/cgi-bin/hn1913.cgi?place=hernad
Kecsõ, Gömör és Kis-Hont megye, Hungary
Kečovo, Slovakia [gemer region]
1773, 1808, 1863–1913, 1938–1945 Kecső, 1786 Kecschő, 1920 Kečovo, 1927–1938, 1945–1948 Kečovo, Kecső, 1948– Kečovo [all the names this location was known by]
If you would share the ancestor's surname, I'm sure we could find the location for you.