Prontera Culvert

live since September 2026 Base Lv. 60+ Grade IV Party required, daily instance

The sewers under Prontera. The whole run hangs on the Ancient Thief Bug eggs: they summon the boss, and clearing the ones in the boss room too earns a second chest.

The entrance

Culvert Manager /navi prt_fild05 265/208

Leave Prontera through the west gate and keep east along the field. Talk to him in a party, otherwise the instance is not created.

Instance map: prt_sewb1
Reset: daily, UTC+0
Final boss: Ancient Golden Thief Bug

Which mode

Normal Less pressure

Goal: Clear the eggs, summon the boss, kill the boss.

Loot: Crystals, plus the Subjugation ring and boots.

Schwer Stronger monsters and a stronger boss

Goal: The same route, but the boss fight forgives less.

Loot: Considerably more crystals, plus Shimmering Opal, Mithril and refine materials.

The route

Form a party, speak to the manager and have the instance created.
Decide the difficulty before the run: Normal gives the base pieces, Hard gives the materials.
Walk every side branch and destroy all the eggs - the boss depends on them.
Before landing the killing blow, search the boss room: leftover eggs cost you the second chest.
Kill Ancient Golden Thief Bug and stay out of the poison patches.
Every party member collects their chest before anybody leaves.

What matters

The eggs are the objective

Progress hangs on the eggs, not on the monsters. One missed egg in a side room stalls the party or costs the bonus chest.

Poison patches in the boss fight

The boss lays down patches that keep ticking. Stepping out is cheaper than tanking them.

Seven or more means more equipment

A party of seven or more gets more pieces out of the Normal chest. Below seven nothing is lost, there is just less of it.

What to bring

Fire resistance for the boss fight.
Fast single-target attacks for the eggs - they have almost no HP, this is about speed.
Antidotes and healing, and keep moving.
Stay together so that no side room is skipped.

What stands inside

Monster	Level	HP	Race	Element	Size
Sewer Giant Thief Bug	60	3,330	Formless	Dark 1	Medium
Sewer Thief Bug	60	200	Insect	Neutral 3	Small
Ancient Thief Bug Egg	60	10	Insect	Dark 1	Small
Ancient Golden Thief Bug Boss	60	1,200,000	Insect	Fire 1	Large

What is in the chest

Normal

Faintly Glowing Crystal 1-3
Subjugation Team's Ring 0-2, with 7+ players 1-3
Subjugation Team Boots 0-2, with 7+ players 1-3

Hard

What the gem is for

Shimmering Opal Earrings 15 × Shimmering Opal + 10 × Mithril Ore · Suspicious Processor

/navi morocc_in 76/167

The gem only drops on Hard. What the finished piece gives is on its item page.

Enchanting

Subjugation and Expedition equipment share one enchant system. The base pool rates, the costs and the essences from +9 upwards are on the equipment page.

Enchant Guild Staff Enchants Subjugation and Expedition equipment.

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The full equipment ladder with recipes and rates →

As of 2026-09-22