Gwynn is located at a fountain in Pokemon Legends: Z-A. The most commonly cited location is the Clawitzer Fountain in Bleu Sector 7 near city hall, where you’ll encounter Gwynn during Main Mission 19 as you progress toward Reaching Rank D. Another walkthrough path places Gwynn at a fountain in Centrico Plaza near Nouveau Cafe, depending on the exact dialogue and mission progression you’re following. Here’s a concise guide to pinning down her location and proceeding:

• Start by advancing to Main Mission 19: Reaching Rank D and follow the on-screen prompts to locate Gwynn. In many guides, the quest directs you to check at city hall first, then to nearby fountains, before the sewers sequence. If you reach Centrico Plaza and Nouveau Cafe, you may find a hint or a different fountain route, depending on your choices and the game’s branching prompts.

• If you’re at city hall, look for a fountain on the east or north side of the area (the bystander dialogue often directs you to talk to someone near the fountain to trigger the next step). This path aligns with the bystander-quest walkthrough that mentions a fountain near City Hall.

• If you’ve already encountered the sewers or you have Ice Beam, you may be redirected to freeze the Clawitzer fountain to unlock access, which is a widely noted strategy in recent guides for this mission. This route confirms the fountain’s location as the Clawitzer fountain in Bleu Sector 7.

What to do at the fountain once you find Gwynn:

• Speak with Gwynn to advance the mission and proceed with the next steps toward completing Main Mission 19 and the broader objective of defeating Ivor. The fountain encounter is a setup for the subsequent events, including possible sewer exploration or further investigation as dictated by the mission branch.

If you’d like, I can pull fresh, precise confirmations from up-to-date guides or video walkthroughs to match your exact in-game progress and platform (Switch/PC) and give you a step-by-step route tailored to your save file.