About: http://webisa.webdatacommons.org/248210995

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	It is still a nice article though!Another thingie:I forgot to mention that an important aspect of an obstacle is that it must be obvious to a player that it is indeed is an obstacle.
http://www.w3.org/ns/prov#wasQuotedFrom	blogspot.com