If by safe, you mean able to get all your money out at any time without risk of loss — then NO there are no investments. You can buy Treasury bills at www.TreasuryDirect.gov, and they mature every 3 or 6 months, and will keep up with rising rates. But the Fed is keeping rates artificially low. You might do a bit better than bank CDs, but not much better with T-bills.
Now, if you want to close your eyes and not look –and never think about withdrawing — I can tell you that a diversified portfolio of American large company stocks with dividends reinvested (think S&P 500 index fund) has always beaten inflation over every 20 year period going back to 1926. Do you have that long a time horizon??