Complex sentence: In 1959, a new exhibition grounds opened in Sderot Rokach beyond the Yarkon River initiated by then Mayor Haim Lebanon along with "Exhibition 50 years of Tel Aviv" and a design plan for a "Fair Middle" by architect Arieh Elhanani.
Split into simpler sentences: In 1959, a new exhibition grounds opened in Sderot Rokach, beyond the Yarkon River. The grounds were opened by then Mayor Haim Lebanon, along with "Exhibition 50 years of Tel Aviv" and a design plan for a "Fair Middle" by architect Arieh Elhanani.