Gate Seal

(Forgotten Realms Campaign Setting, DnD 3.0)

Abjuration

Level: ; Bard 6; Cleric 6; Druid 6; Sorcerer/Wizard 6
Components: V, S, M
Casting Time: 1 action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One gate or portal
Duration: Permanent
Saving Throw: None
Spell Resistance: No

You permanently seal a gate or portal.
Gate seal prevents any activation of the gate or portal, though the seal may be negated by a successful dispel magic cast upon the spell.
A knock spell does not function on the gate seal, but a chime of opening dispels the spell.
Material Component: A silver bar worth 50 gp.