Once you claim your landmark, you'll be able to set a new goal. If you're watching ads, your progress will automatically restart from 0. Please note that your progress only resets once you've claimed your landmark. Be sure to claim your landmark to ensure your progress resets and any additional ads you watch are counted towards a new landmark! Once you claim a landmark, you can choose whether to construct it in your current plan or a future plan. The landmark will match whichever theme you decide to construct it in.
Learn more: How can I get new landmarks?