Where to catch Nidoran♂

In Johto & Kanto (Gold, Silver & Crystal)

• National Park — Walk
• Route 35 — Walk
• Route 36 — Walk

In Kanto (Red, Blue & Yellow)

• Route 10 — Walk
• Route 2 — Walk
• Route 22 — Walk
• Route 9 — Walk
• Safari Zone — Walk

Nidoran♂ — full Pokédex entry