The locate city bomb is a series of metamagic feats you can apply to a the locate city spell to do high damage over a very wide area.
Cast locate city from Races of Destiny.
Use the Snowcasting feat from Frostburn to add the Cold descriptor to locate city.
Use the Flash Frost feat from Player’s Handbook II, which can only be applied to cold spells, to add 2 cold damage to all creatures within the area of the Snowcasted locate city.
Use the Energy Substitution feat from Complete Arcane, which can only be applied to a spell that deals acid, cold, electricity, or fire damage, to turn the cold damage to electricity damage.
Use the Born of the Three Thunders feat from Complete Arcane, which can only be applied to an area spell with the electricity or sonic descriptor that deals hit point damage. Among other things, this forces creatures within locate city’s area to make a Reflex save.
Use the Explosive Spell feat from Complete Arcane, which can only be applied to a cone-, cylinder-, line-, or burst-area spell that allows a Reflex save, to force those within who fail the Reflex save to the edge of the effect, taking 1d6 damage for every 10 feet moved.
If the locate city spell were banned, what other spells could use this combination of feats to produce a similar effect?
The locate city spell has a radius of 10 miles/level; I'd consider a spell to have a similar effect if its area of effect was also very large (and if the rest of the locate city feat stack worked with it).