A second fortress: king on the back rank, pawn on g7 shielding it, rook on f7 protected by king and pawn. The queen cannot attack anything without allowing a rook check or trade.
Here the fortress is built one rank further back. The black king on g8, pawn on g7 and rook on f7 protect one another in a chain: the king protects both the pawn and the rook; the rook on f7 covers the seventh rank and the f-file; the pawn on g7 shields the king from checks along the g-file and the long diagonal.