In the northeast corner of Jerusalem’s wall, a gate was located through which (presumably) sheep could be herded for slaughter in the temple just inside that section of the wall (John 5:2). Travellers from afar would then also favour this gate because they could purchase a sheep here for their own sacrifices. It is logical that Eliashib and his brethren would labour to rebuild this section of the wall since they would have a vested interest in the wall nearest to temple access.
1 Then Eliashib the high priest rose up with his brothers the priests, and they built the Sheep Gate. They consecrated it and set its doors. They consecrated it as far as the Tower of the Hundred, as far as the Tower of Hananel.