Question: What's the waterfall in the country containing Glassblock Dam?

full_context: Document 1: Gadzema: Gadzema is a village in the province of Mashonaland West, Zimbabwe. It is located about 110 km south-west of Harare on the main Harare-Bulawayo railway line. The village grew up around the a railway station that was built on the line. It was named after a nearby hill, "Ganidzima Hill", which means ""a shining place"". Gold was discovered in the area and in 1905 the Giant Mine was opened by is now closed. In 1920 the station was closed and is now just operated as a siding.
Document 2: Mtetengwe River: The Mtetengwe River is a tributary of the Mzingwane River in Beitbridge District, Zimbabwe. There are two dams on its tributaries: Tongwe Dam on the Tongwe River, which provides water for an irrigation scheme, and Giraffe Dam which supplies water for cattle.
Document 3: Chavuma: Chavuma is a town in North Western Zambia, lying immediately south of the border with Angola. The town is approximately 1,100 kilometers from Lusaka and 11 kilometers from the Angolan border town of Kalipande. It lies on the Zambezi River and the M8 road. Local attractions include the Chavuma Falls, while a market takes place on the border, permitting people from both nations to trade.
Document 4: Kwena Dam: Kwena Dam is a combined gravity & arch type dam located on the Crocodile River, near Lydenburg, Mpumalanga province, South Africa. It was established in 1984 and it serves mainly for irrigation purposes. The hazard potential of the dam has been ranked high (3).
Document 5: Manyuchi Dam: Manyuchi Dam forms a reservoir on the Mwenezi River in southern Zimbabwe. It is located in the Mwenezi District. The building of the dam was financed by the Mwenezi Development Corporation. The dam was built to irrigate oil palm estates.
Document 6: Victoria Falls: Victoria Falls (Tokaleya Tonga: Mosi - oa - Tunya, ``The Smoke that Thunders '') is a waterfall in southern Africa on the Zambezi River at the border between Zambia and Zimbabwe.
Document 7: Zhovhe Dam: Zhovhe Dam is a reservoir on the Mzingwane River, Zimbabwe with a capacity of 133 million cubic metres. It supplies water for commercial irrigation and the town of Beitbridge.
Document 8: Glassblock Dam: Glassblock Dam is a proposed reservoir on the Mzingwane River, north of Gwanda, Zimbabwe with a capacity of 14 million cubic meters.
Document 9: Niagara Falls: Located on the Niagara River, which drains Lake Erie into Lake Ontario, the combined falls form the highest flow rate of any waterfall in the world that has a vertical drop of more than 165 feet (50 m). Horseshoe Falls is the most powerful waterfall in North America, as measured by flow rate. The falls are 17 miles (27 km) north - northwest of Buffalo, New York, and 75 miles (121 km) south - southeast of Toronto, between the twin cities of Niagara Falls, Ontario, and Niagara Falls, New York.
Document 10: Nooitgedacht Dam: Nooitgedacht Dam is an earth-fill type dam located on the Komati River in South Africa. It was established in 1962 and serves mainly for irrigation purposes as well as municipal and industrial use. The hazard potential of the dam has been ranked high (3).
Document 11: Berlin Falls: The Berlin Falls is a waterfall in Mpumalanga, South Africa. They are located close to God's Window and the highest waterfall in South Africa's Mpumalanga province, Lisbon Falls. Whilst less than a tenth of the heigh of South Africa's tallest waterfall, the Tugela Falls, they are nonetheless extremely beautiful.
Document 12: Niagara Falls: Niagara Falls is the collective name for three waterfalls that straddle the international border between the Canadian province of Ontario and the American state of New York. They form the southern end of the Niagara Gorge.
Document 13: Nyambwezi Falls: Nyambwezi Falls are a waterfall located in the North-Western Province of Zambia. They are approximately high. Close to the lip of the falls, there is a rock shelter, which has petroglyphs and other evidence of late Stone Age occupation.
Document 14: Manjirenji Dam: Manjirenji Dam, formerly known as Lake McDougal, lies in south eastern Zimbabwe, east of Masvingo. It was built to provide irrigation water to the farming estates on the lowveld to the southwest, around the town of Chiredzi, where the main crop has been sugar cane.
Document 15: Victoria Falls: Victoria Falls (Tokaleya Tonga: Mosi - oa - Tunya, ``The Smoke that Thunders '') is a waterfall in southern Africa on the Zambezi River at the border between Zambia and Zimbabwe. It has been described by CNN as one of the Seven Natural Wonders of the world.
ground_truth: Victoria Falls
sub_queries: Glassblock Dam >> country Answer: Zimbabwe
what is the name of the waterfall in Zimbabwe Answer: Victoria Falls