Tunnels

Tunnels follows 14-year old Will Burrows who like his father, is very interested in digging. Then one day his father disappears so Will and his friend Chester try and find him. In his cellar, they find a passageway behind some bookshelves. They re-excavate it and eventually come across a door set into the rock, with three large handles. Going through the door they go down in an old lift and, to their surprise, eventually arrive on a cobblestone street. Lit by a row of lamps resembling larger versions of Dr Burrows' luminescent orb, there are houses that appear to be carved out of the walls themselves. (Source: Wikipedia)

Based on a series of novels by UK authors Roderick Gordon and Brian Williams, this manga is illustraed by Shigeru Kimuraen. Some links can be found under more info.