TORONTO, Canada’s largest city, has expansive views across Lake Ontario. For the past 35 years, tourists have flocked to an observation deck at CN Tower’s needle-like spire, which at 553m is still ranked as one of the world’s tallest structures. From August 1, brave visitors attached to harnesses will be able to enjoy the scenery via the adrenalinpumping exterior Edge Walk, 116 storeys up and touted as the ‘‘world’s highest full-circle hands-free walk’’. The thrilling experience takes 90 minutes; for $C175 ($170), the victorious also take home a video, photos, certificate and, of course, heartstopping memories. More: edgewalkcntower.ca. ARMCHAIR TRAVELLER Midsomer Murders: The stonyfaced Neil Dudgeon is brilliant as the new DCI John Barnaby, a fine replacement for the recently retired John Nettles character; and there are as many corpses and village mysteries as ever in this oddly dangerous English county with its foreverlurking murderers. Sunday, 8.30pm, ABC1. Big, Rich Texas: A rivetingly ghastly fly-on-the-mansionwall series opener on diva mothers and their princessy daughters in good ol’ Dallas; it’s hair-dryers at dawn and not so much a matter of ‘‘who shot JR?’’ as who’s going to stiletto-stab who first. Tuesday, 8.30pm, Style.