I have attempted to improve:  
A. The top 500m of the Snowdon Mountain railway, 
B.  The top 500m of the Llanberis Path, from the junction with the Pyg Track to the summit, 
C.  The summit point and tracks and steps around it.  
All edits based on DigitalGlobe Premium imagery, validated by my GPS trace of 21/06/2018 on the Llanberis Path. I think that the DigitalGlobe Premium imagery is less distorted than the Bing imagery, although it shows the summit a few metres North of where my GPS trace puts it.  I hope that helps. I could not find the circular walk around the summit; perhaps it has fallen down the cliff face?