Lost grotto is a (underground) point of interest in Lion's arch, near Trader's Forum waypoint and near the eastern ward, in Guild Wars 2. :) https://youtu.be/3ff9MSzQO_s
This is the White Crane Terrace vista, at Diverse Ledges waypoint, in Lion's Arch. (Way 2), in Guild Wars 2. :) https://youtu.be/GCuwAoOA9co
This is the White Crane Terrace vista, at Diverse Ledges waypoint, Lion's Arch, in Guild Wars 2. :) https://youtu.be/DFV9Lp5kutA
This is the Sharkmaw caverns vista, in Lion's Arch, Guild Wars 2. :) https://youtu.be/TlvstONSRJ0
You will find the vista in Kessex Hills (Viathan's Arm area), under the toxic alchemist. Just start at Ireko Tradecamp waypoint and follow the video. :) https://youtu.be/wZOUQozwOHc
This is a really short and easy jumping puzzle that you can find on the Pearl Islet, in Southsun Cove, Guild Wars 2. :) https://youtu.be/fStDbg-pCPU
This is a video of Lion's Arch easiest JP (Urmaug's Secret). Very easy and short jumping puzzle. :) https://youtu.be/t_PJoluXVDc