Rainbow Falls could be an area. There would be an arena there because that's where the Wonderbolts train. You could also trade items with merchants at the Trader's Exchange.
Fire Geyser Swamp could also be an area. You would need fire proof boots to enter it. There would be a side-quest to deliver apples to a certain pony and you would fight the Chimera as a boss. It would use fire attacks obviously.
http://img4.wikia.nocookie.net/__cb20140...79p1g9.png
Also, I found a really good sprite for Queen Chrysalis! http://fc04.deviantart.net/fs71/f/2013/0...5wur6w.png (Be sure to credit lordsiravant.) You should probably use it on the field instead of the vector, it would look a lot better.
I found a King Sombra sprite as well, i'd imagine that it would be useful: http://fc00.deviantart.net/fs70/f/2013/1...6dst8a.png
Fire Geyser Swamp could also be an area. You would need fire proof boots to enter it. There would be a side-quest to deliver apples to a certain pony and you would fight the Chimera as a boss. It would use fire attacks obviously.
http://img4.wikia.nocookie.net/__cb20140...79p1g9.png
Also, I found a really good sprite for Queen Chrysalis! http://fc04.deviantart.net/fs71/f/2013/0...5wur6w.png (Be sure to credit lordsiravant.) You should probably use it on the field instead of the vector, it would look a lot better.
I found a King Sombra sprite as well, i'd imagine that it would be useful: http://fc00.deviantart.net/fs70/f/2013/1...6dst8a.png