Senin-bong is located in Dobongsan, which is located in the northeastern part of Bukhansan National Park. Like Insu-bong, it features high quality, granite climbing. Many consider Seninbong to have just as many, if not more quality crack routes than Insu-bong with fewer crowds. 

Lodging: You can stay in the area or anywhere in Seoul for a good balance of city and nature life. Stay near the 1 line if you are taking public transportation. 

Gear: Depends on how clean you want to climb (Seninbong is not as heavily bolted as Insu but still is for sure), but I would recommend at least a full rack of cams and some wide gear. 60m rope would suffice but a pull cord/tag line would be very useful. 

For public transit, take the 1 line to Dobongsan train station (도봉산역), take the 1 exit, and make your way west towards Dobongsan/Senin-bong. If you're walking towards a huge, beautiful, granite peak that looks like the pictures uploaded, you're going the right way :)

If you are accessing by car, type in Dobongsan Public Parking Lot (도봉산공영주차장) in your Naver Maps to get to the base of the approach trail. Park here and start your journey. Note: the parking lot is kind of expensive (I think 2 or 3,000 won for 1 hour, half price for compact cars) and I have not found an alternative parking spot to date. After racking up, pass by the plethora of outdoor gear stores, street food carts and hiking gear shops to the base of the main trail. There are many ways to the base of Seninbong, but to get to the left most routes of Senin-bong towards the routes 'Leopard' and 'Bat', I navigated up the trail towards '석굴암'. At one point there will be a big fork in the road and it'll seem like going left is the more direct route, but stay right towards the direction of 석굴암. You will cross a river bed, pass by a ranger station on the left with bathrooms, and go up the route with many stairs. Towards the end, take the stairs towards temple and take a climbers path right before the first building. There are some black rubber water pipes and worn rock as a marker (see pictures). Scramble your way up and you will soon be in front of the staging area.