Poor behaviour is not only a barrier to learning it can also threaten the health and wellbeing of education professionals. (atl.org.uk)
Kayak over the protected waters of Kaneohe Bay to Coconut Island, aka «Gilligan's Island,» and snorkel on Oahu's only barrier reef on this tour from Waikiki. (hawaii-travelguide.com)
Only the barrier of separation must be destroyed, and this can not be done through any formula, precept, or spiritual exercise. (religion-online.org)