His instructions on this point deserve the closest study, for he foresaw the inevitable attraction which a complete entrenched camp would exercise even upon himself, and, therefore, limited his engineers to the construction of a strong bridge head on the right bank and a continuous enceinte, broken only by gaps for counter attack, around the town itself.
At Antwerp the old citadel and enceinte were removed.
The size of the city was diminished by the retrenchment of nearly one-third at the northern end, which brought the enceinte more nearly to a square form.
The old ramparts and bastions (excluding the circuit of the citadel of 1591, now in great part demolished, in the south-east) make an enceinte of about 41 m., but the enclosed area is not all occupied by streets and houses.
Each of the sixteen gates of the city is protected by a semi-circular enceinte, and is surmounted by a high tower built in galleries and provided with countless loopholes.